Question

Which from following is the most stable species?

• A. \(\mathrm{NH}_{4}^{+}\)
• B. \(\mathrm{R}-\overset{+}{\mathrm{N}}\mathrm{H}_{3}\)
• C. \(\mathrm{R}_{2}\overset{+}{\mathrm{N}}\mathrm{H}_{2}\)
• D. \(\mathrm{R}_{3}\overset{+}{\mathrm{N}}\mathrm{H}\)

Hint:

Alkyl groups release electrons and spread out the positive charge on nitrogen, so more alkyl groups mean more stability.

Answer 1

The Correct Option is D

Step 1: Inductive effect
Each $\text{R}$ pushes electron density toward the positively charged nitrogen.

Step 2: Effect of more groups
The more electron donating groups present, the smaller the effective charge on N.

Step 3: Result
Three alkyl groups are present in $\text{R}_3\text{NH}^{+}$, so it is the most stable species.

Final Answer:
$\text{R}_3\text{NH}^{+}$ is the most stable. \[ \boxed{\text{(D) }\text{R}_3\text{NH}^{+}} \]